Attachment for elevators.



PATENTED JULY 5, 1904.

0. OHRISTIANSEN.

ATTACHMENT FOR ELEVATORS.

APPLIOATION FILED DEC 30, 1903.

2 SHBBTS SHEIH 1.

N0 MODEL.

Wii gesszs v PATENTED JULY 5, 1904.

0. GHRISTIANSEN.

ATTACHMENT FOR ELEVATORS.

APPLIUATION FILED DEC. 30. 1903.

2 SHEETS-SHEET 2.

N0 MODEL.

UNITED STATES Eatented July 5, 1904.

PATENT OFFICE.

ATTACHMENT FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 763,960, dated July 5, 1904.

Application filed December 30, 1903. Serial No. 187,213. (No model.)

To all whom it nuty concern:

Be it known that I, CHRISTOPHER CHRISTIAN- snN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Attachment to Elevators, of which the following is a specification.

This invention relates to attachments to elevators, and more especially to attachments to passenger-elevators.

It is a desideratum of prime importance in elevators generally to relieve the car-hoisting mechanism as far as may be possible of all unnecessary strains both for the purpose of diminishing the power required to operate the elevator and in order to reduce the wear upon the winding apparatus to a minimum. To this end it is customary to provide a heavy counterweight or other devices to balance the weight of the elevator-car and to resist its .ing the elevator-car the hoisting mechanism is subjected to a heavy strain when the car is loaded, thus making the cost of running the elevator quite large on account of the consumption of power necessary to operate the hoisting mechanism.

The present invention has for its object the provision of an attachment for elevators whereby the load placed upon the elevator will be effective to increase the resistance to the descent of the elevator-car, so as to relieve the hoisting mechanism of a considerable portion of the strain during the descent of the elevator-car and to cause the descent of a heavily-loaded elevator-car to effect the storage of a considerable amount of power,

which may be made use of to raise the ele vator-car with a smaller load therein or to assist the hoisting mechanism in raising the car when heavily loaded.

A further object of the invention is to provide, in connection withan elevator, an automatically-operative attachment whereby the resistance to the descent of the elevator-car will be proportioned to the load in the elevator-car, and so relieve the hoisting mechanism of unnecessary strain.

A further object of the invention is to provide an elevator with automatically-operative devices for-making the counterbalancing action of the descent resisting mechanism of the elevator directly proportional to the load upon the elevator, whether the load be acquired at once or at intervals during the movement of the elevator-car either up or down.

In attaining the objects above stated I make use of the novel construction, combination, and arrangement of parts of an attachment for elevators, as hereinafter described and claimed.

In describing the invention in order to make the nature and use of the same clear to persons skilled in the art I shall refer to the accompanying drawings, forming a part of this specification, in which I have. illustrated a preferred form of embodiment of the invention, it being understood that changes in the details of construction may be resorted to without departing from the spirit of the invention or sacrificing the advantages thereof.

In the drawings, Figure 1 is a view in elevation of the upper portion of the framing around an elevator-shaft, showing the attachment forming the present invention in operative relation to said framing. Fig. 2 is a view in elevation of the structure shown in Fig. 1, the view being taken from the left side of Fig. 1. Fig. 3 is a detail view showing the preferred mode of connecting an air-compressing apparatus with the elevator attachment.

Referring to the drawings, in which corresponding parts are designated by similar charactors of reference, F represents the framing at the top of the elevator-shaft, and comprises uprights 1, transverse members 2, arranged at opposite sides of the shaft, and lowertransverse members 3, which hold the uprights 1 IOO in fixed relation. Arranged at the top of the framing F and substantially over the center of the elevator-shaft is a rock-shaft 1, mounted in bearings 5 upon the transverse members 2. Upon the upper surface of the rock-shaft v at there is rigidly secured at right angles thereto a lever 6, one end of which is yieldably supported at one side of the elevator-shaft, preferably by means of a spiral spring 7, which is wound around a guide-rod 8, supported in a transverse timber 9, connecting the upper portions of the uprights 1 and arranged to limit the pivotal movement in one direction of the lever 6. The guide rod 8 extends through an opening provided for that purpose in the end of the lever 6 and serves to prevent any considerable degree of lateral swing of the lever. At the other end the lever 6 is reduced in diameter and rounded to form a pivot portion 10, upon which is pivotally supported a lever 11. fulcrumed upon a pin 12, which is mounted in a bracket 13 upon one of the uprights 1. The other end of the lever 11 is rounded to form a pivotal portion 1t, which extends through an opening in the end of a connecting rod or bar 15, the lower end of which is pivotally connected with the free end of a lever 16, pivoted at the opposite end upon a pivot-pin 17. extending from the outer surface of a board or piece of framing 18, secured upon two of the uprights 1. Upon the outer surface of the board or piece of framing 18 are secured two vertical members 19 and a transverse member 20, connecting the vertical members and forming,

together with the lever 16, a guideway for a plurality of vertical sliding weights 21, the weight of which is normally borne by a member 22 at the bottom of the guideway and securely fastened to one of the transverse memhers Each of these weights is provided on its outer surface with a projecting stud 23, and the studs are so arranged that when the weights are all supported by the member 22 said studs will form an oblique line, as best seen in Fig. 1. W' hen thelever 16 is depressed as far as the movement of the lever 11 will permit, all of the weights 21 have their lower ends resting upon the member 22 beneath them; but when the lever 16 is raised it will engage successively the several studs upon the outer surface of the weights and will raise out of contact with the member 22 a number of weights, the exact number raised being dependent upon the amount of elevation of the lever 16. When the lever 16 is raised to its fullest extent, all of the weights are lifted from the member 22 and are supported upon the lever 16.

The elevator-car is suspended in an elevator-shaft by a suitable cable or cables, and in the structure illustrated the car-supporting cable is designated as 25. The cable 25 passes over a pulley 26, supported by the lever 6, to which it is attached adjacent to the rock-shaft upon which the lever is fulcrumed. The pulley 26 is substantially over the center of the shaft, and the portion of the cable extending downward from the pulley is understood to be secured to the elevator-car (not shown) in any ordinary or preferred manner. The cable 25 passes from thepulley 26 to the side of the elevator-shaft and there passes around the large end of a cone-pulley 27, which is provided with grooves 28 to receive it. The cone-pulley 27 has its axis disposed horizontally, as shown, and is supported in a suitable framef, attached to the uprights 1 of the framing around the shaft of the elevator.

in order to secure sufficient frictional contact of the cable 25 with the pulley 27, guidepulleys 29 and 30 are supported upon a suitable supporting structure adjacent to said cone-pulley, and the cable 25 is passed over the cone-pulley, then around the guide-pulley 30, around the cone-pulley a second time, and then over the guide-pulley 29, from which the cable extends downward to the winding mechanism, which may of course be of any suitable character.

Below the cone-pulley 27 there is rotatably mounted in the frame F a similar cone-pulley 31, which is arranged in the reverse position to that of the cone-pulley 27 and a belt 32 encircles the two cone-pulleys, so that the retation of either will impart rotation to the other, the relative rates of rotation being dependent upon the position of the belt upon the two pulleys. In order to determine the position of the belt 32 upon the pulleys 27 and 31, a belt-guide is provided, and in the present instance the preferred form of beltguide includes the horizontally-arranged bar 33, extending through openings in upright members of the frame F about, midway between the two cone-pulleys. The bar 33 is freely slidable in the openings in which it is secured and is provided upon either side with spaced projecting arms 34:, between which the two leads of the belt 32 pass. In order to shift the bar 33, and so impart lateral movement to the belt 32, a stud 35 is provided upon the outer side of the bar,and a bell-crank lever 36 is fulcrumed at the top of the frame F and has one arm provided with a slot through which the stud 35 passes, and the other arm is provided with a similar slot for the reception of a stud 37, secured in the end of the lever 6.

From the foregoing description of the apparatus it will be seen that the weight of the elevator-car is transmitted through the cable 25 to the pulley 26, supported by the pivoted lever 6, and as the pulley is not beneath the fulcrum of the said lever the weight of the car and. its lead. tends to rock the lever upon its fulcrum. The movement imparted to the lever by the loaded car tends to depress the end of the lever resting upon the spring 7 and to raise the opposite end of the lever.

The

spring 7 is designed merely as a buffer and is not intended to support any considerable portion of the weight of the car and-its load, so that if no other means were provided to check the pivotal movement of the lever 6 under the weight of the car the spring 7 would always be compressed to the full limit of compression whenever any load was sustained by the cable 25; but the end of the lever 6 opposite the spring 7 extends through the lever 11, fulcrumed in the bracket 13, and the downward movement of the end of the lever 6 above the spring 7 is accompanied by an upward movement of the other end of the lever which carries with it the lever 11. As pointed out in a preceding paragraph, the upward movement of the lever 11 carries with it the connecting rod or bar 15 and the lever 16, pivotally connected with the connecting-rod at its lower end. The upward movement of the lever 16 brings it successively into contact with the studs 23, which project from the outer faces of the weights 21, and as the lever 16 is raised a steadily-increasing resistance to its upward movement is encountered. (Jonsequently the depression of one end of the lever 6 by the weight of the elevator-carand the load contained therein will be gradually arrested by the increase of load upon the lever 16 as it rises. The point at which the rise of the lever 16 is stopped ,will depend upon the size of the load in the elevator-car, as will be readily understood. W hen the elevatorcar has a very light load, one or two only of the weights 21 will be lifted by the lever 16, and a very slight depression of the pulley 26 and the adjacent portion of the lever 6 will occur. iVhen, however, a heavy load is carried by the elevator-car, nearly all of the weights 21. will be lifted by the lever 16, and the lever 6 will be rocked upon its fulcrum to nearly the full limit of its range of movement.

As the bell-crank lever 36 is operatively connected with one end of the lever 6, the upward movement of that end of the lever when the elevator-car is loaded will impart move ment to the bell-crank lever in the direction indicated in Fig. 1, and themovement of the bellcrank lever will be imparted to the sliding bar 33 and to the projecting belt-guiding arms 34. The movement of the lever 6 when the load is placed in the elevator-car will causethe bar to travel to the left, as seen in Fig.

1, and the belt 32 will be shifted in the samewill impart to the pulley 31a rate of rotation that is only slightly greater than that of the pulley 27. Witheach addition to the load in the elevator-car,however,there will be a slight lateral movement of the belt 32, and when the car is loaded to its full capacity the belt will be in such positionupon the two pulleys that the pulley 31 will rotate at a much more rapid rate than'the pulley 27.

The difference in the rates of rotation of the pulleys 27 and 31 is made use of to vary the resistance to the descent of the car and to make the resistance of the descent of the car at all times proportional to the load carried thereby. This resistance to the descent of the car may be obtained in various ways. The simplest method is, perhaps, to provide a windingdrum upon the axis of the pulley 31, as shown at 40, and to have a cable 41 connected with a counterweight-hoisting mechanism of any suitable character, as indicated in Fig. 1 at 42. When such mechanism is provided, the amount of movement imparted to the counterweight 43 will depend upon the load carriedby the elevator-car, because the rate of rotation of the pulley 31 will be proportional to the load carried by the car.- As the amount of mechanical work done in lifting a weight is dependent upon the magnitude of the weight and upon the height to which it is lifted, the mechanical work done upon the counterweight when the elevator-car descends -will be directly proportional to the load in the elevator-car, the height to which the weight is lifted being determined by the load in the car.

Other forms of resistance devices may be substituted for the counterweight lifting mechanism described in the preceding paragraph, if preferred. For example, the pulley 31 may have attached to the shaft thereof an aircompressing mechanism, diagrammatically indicated at 45 in Fig. 3, and then the amount of air compressed will be determined by the load in the elevator-car when it descends, and consequently the amount of resistance to the descent of the loaded car Will be proportioned to the load carried by the car in its descent."

If still other forms of resistance devices are preferred to the counterweight or aircompressor above mentioned, they may be operatively connected with the pulley 31 and results of similar character may be obtained; but as the exact nature of the devices to be operated by the pulley 31 to afford resistance to the descent of the elevator-car doesnot form an essential part of the present invention it is deemed unnecessary to describe such devices in detail or to enumerate a great variety of mechanisms to store up power when driven by the rotation of the pulley .31.

From the foregoing description of my invention and the drawings illustrative thereof it will be readily seen that the mechanism is IIO entirely automatic in operation and is so constructed that it is practically impossible except in case of breakage of some integral part thereof for the apparatus to fail to operate. It will also be seen that the parts of the apparatus are so designed and arranged that sudden strains cannot be applied thereto, and consequently the liability of any portion of the apparatus to breakage is very slight.

For the sake of simplicity in illustration a single car-su pporting cable only is illustrated, and the winding mechanism by means of which the ear is raised and lowered has not been described or shown. It is to be understood, however, that a plurality of cables may be and ordinarily will be employed to support the elevator-ear, and any approved type of hoisting mechanism may be used.

The car-supporting cables will in all cases be so arranged as to have sufficient frictional contact with the grooved end of the cone pulley 27 to insure the rotation of the conepulley when the car descends and to prevent any slipping of the cable upon the pulley. The belt 32 by means of which rotation is imparted from the pulley 27 to the pulley 31 during the descent of the car is of course of suflicient strength and has frictional engagement with the pulleys to impart the desired rotation from one to the other without loss of motion from slipping of the belt upon either pulley.

As the descent of the loaded elevator-car will always cause the rotation of the pulley 31 and will lift a counterweight or operate another form of resistance mechanism, a certain amount of power will always be stored when the car has completed its descent, and when the ear is loaded for ascent the power stored up by the descent of the car will tend to rotate the pulley 31 in a direction opposite to its direction of rotation during the descent of the ear and will so assist the winding mech anism to raise the loaded car, as the pulley 31 will then become a driving-pulley and will impart movement to the pulley 27 in the direction opposite to that of its rotation during the descent of the car. If the load carried down by the elevator-car is large and the load placed on the car for ascent immediately afterward is somewhat smaller, the power stored up through the operation of the pulley 31 during the descent of the car will always be effective upon the next ascent of the carto assist the ear-hoisting mechanism. As the position of the belt connecting the cone-pulleys is determined by the load in the car, the amount of power imparted to the car from the descent-resisting mechanism upon any ascent of the car will not exceed the amount necessary to counterbalance the load in the car. Consequently whatever the load upon the car the amount of strain upon the hoisting mechanism in raising the car after the descent-resisting mechanism has been in operation will be substantially the same.

From the foregoing description it will be clearly seen that the attachment for elevators is adapted to make effective use of the power obtainable from the descent of a loaded elevator and to control the expenditure of such power in such a manner as to make the expenditure of energy necessary in hoisting the elevator practically uniform with loads of widely-varying sizes and to greatly reduce the total amount of energy required in operating the elevator.

In explaining the operation of this invention it has been assumed that the loads carried upward by the elevator will in the aggregate just equal the loads carried downward by the elevator. It is of course understood thatduring certain portions of each day the loads carried in one direction are much larger than those carried in the other direction. Thus in the evening the loads carried downward. are usually a great deal larger than those carried upward, while in the morning the reverse is true. To allow for this variation in the loads carried in each. direction at different times during each day, it is necessary that the apparatus be of considerable capacity to store power; but with an apparatus of large capacity for the storage of power it is obvious that a great saving will be effected in the total expenditure of energy required in the operation of the elevator.

Having thus described the nature and operation of my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a structure of the character specified, a load raising and lowering member, and devices connected with said raising and lowering member and automatically operative at any stage of its descent to oppose to the descent of said raising and lowering member a resistance proportional to the load carried by said member.

2. In a structure of the character specified, a load raising and lowering member, and devices automatically operated by the descent of said member at any stage of its descent to store up during its descent a quantity of power proportional to the load carried by said member.

3. In a structure of the character specified, a load raising and lowering member, devices for resisting the descent of said member, and mechanism automatically operative at any stage of the descent thereof for varying the resistance offered by said descent-resisting devices to correspond to the variations in the load carried by said member.

1. In a structure of the character specified, a raising and lowering member, a counterweight. counterweight-hoisting mechanism, and means controlled by the load on the raising and lowering member at any stage of the descent of said member to operate said connterweight-hoisting mechanism at a rate proportional to said load.

5. In a structure of the character specified, a hoisting-cable, a yieldable support for said cable, and mechanism controlled by the movement of said yieldablesupport tooppose a resistance to the descent of the cable proportional to the load carried thereby.

6. In a structure of the character specified, a load-supporting cable, a movable support for said cable, a plurality of Weights arranged to be successively lifted as said movable support is depressed by additional increments to the load upon the cable, and mechanism controlled by the movement of said movable supporting member to oppose a resistance to the descent of the load proportional to the load.

7. In a structure of the character specified, a load-supporting cable, automatically-variable counterbalancing devices for the load upon said cable, descent-resisting mechanism controlled by said counterbalancing devices, and means for imparting movement from said cable to said descent-resisting mechanism.

8. In a structure of the character specified, a load-supporting cable, Winding mechanism for said cable, a pivoted cable-supporting member, a Weight-lifting member operatively connected with said cable-supporting member, a plurality of Weights adapted to be successively lifted as the load upon the cable increases, descent-resisting mechanism, and controlling devices for said descent-resisting mechanism operatively connected W ith said cable-supporting member.

9. In a structure of the character specified, a load-supporting cable, Winding mechanism for said cable, a cone-pulley driven by said cable, a second cone-pulley arranged oppositely to the first cone-pulley, driving connections between said cone-pulleys, mechanism controlled by the load upon the cable to shift said driving connection to vary the relative rates of rotation of said cone-pulleys, and descentresisting mechanism operatively connected with the last-mentioned cone-pulley.

10. In a structure of the character specified, a load-supporting cable, Winding mechanism for said cable, a cone-pulley engaged by said cable, a second cone-pulley arranged oppositelyto the first-mentioned cone-pulley, a belt connecting said cone-pulleys, belt-shifting means, means controlled by the load upon the cable for operating said belt-shifting means, and descent-resisting mechanism operatively connected With the second cone-pulley.

11. In a structure of the character specified, a load-supporting cable, Winding mechanism for said cable, a pivoted supporting member for said cable, automatically-variable loadcounterbalancing devices operated by said supporting member, descent-resisting mechanism operated by said cable, and mechanism for controlling the rate of operation of said descent-resisting mechanism operatively connected with said pivoted supporting member.

12. In a structure of the character specified, a loadsup1 )orting cable, a pivoted cablesupporting member, a buffer-spring under one end of said pivoted member to cushion its movement, and counterbalancing mechanism operatively connected With the other end of said pivoted member, said mechanism including a plurality of separate Weights adapted to be successively lifted as the end of said supporting member is raised.

13. In a structure of the character specified,

CHRISTOPHER CHRISTIANSEN.

l/Vitnesses:

JOHN ENGDAL, SoLoMoN GREENBAUM. 

